Pathogenic microorganisms directly or indirectly cause a variety of economic, environmental, and medical problems: loss due to spoilage during product distribution in the food industries, harmful effects of excessive pesticide use on human health and the environment in the agricultural industries, and emergence of resistant strains due to misuse or abuse of antibiotics.
Since the first case of vancomycin-resistant staphylococcus aureus (VRSA), which has high-level resistance to vancomycin, the antibiotic of last resort for use against infection with common S. aureus strains, was reported by the Centers for Disease Control in 2002, there has been considerable concern about the spread of so-called super bacteria. Methicillin-resistant s. aureus (MRSA), which is susceptible only to vancomycin, has caused great concern since 1970, and vancomycin-resistant enterococcus (VRE) showing resistance to vancomycin was first isolated in Europe in 1988. In the late 1990's, the appearance of vancomycin intermediate-resistant s. aureus (VISA) was reported in Japan, the U.S.A., France, and Korea. The emergence of these antibiotic-resistant bacteria has now become a worldwide problem, and thus there is an urgent need for the development of new antibiotics (Pfeltz, R. F. and Wilkinson, B. J. 2004. The escalating challenge of vancomycin resistance in Staphylococcus aureus. Drug targets-infect. Disord. 4: 273-294.; Levy, S. B. and Marshall, B. 2004. Antibacterial resistance worldwide: causes, challenges and responses. Nature Med. 10: 122-129.).
Most of the currently used antibiotics are prepared by chemical synthesis, which has many limitations including high costs and the occurrence of side effects. Therefore, recent studies have been actively made to isolate new antimicrobial substances from natural sources. In this regard, it has to be considered whether the antimicrobial substances isolated from natural sources have a broad antimicrobial spectrum and are safe for long-term use without the possibility of side effects.
Meanwhile, oral diseases are generally caused by various kinds of bacteria in the mouth, which can be divided into cariogenic bacteria and periodontopathic bacteria, represented by S. mutans and P. gingivalis, respectively. Several disinfectants have been used in dental care products in order to remove oral bacteria. Examples of the disinfectants used in dental care products include raw materials such as cetylpyridinium chloride, hexylkonium chloride, benzalkonium chloride, dequalinium chloride, chlorhexidine, triclosan, thymol, isopropyl methylphenol, and alkyldiaminoethylglycine hydrochloride, polyphenols isolated from natural products, and silver compounds. In recent years, there has been an increasing interest in the use of natural extracts, and thus many studies have been conducted on a variety of plants, of which effects on oral diseases have been also known. Accordingly, plant extracts have been used in numerous oral compositions for the prevention of oral diseases.
Acne is a common skin disease that induces inflammation at the skin surface of the face, neck, chest or back. Acne develops mostly in young people due to several factors, including hormonal imbalance, bacterial infection, stress, food, or cosmetic application. Especially, Propionibacterium acnes, which is one of major organisms isolated from the surface of skin, induces an inflammation in the sebaceous glands or hair pores. P. acnes secretes lipase and degrades sebum oils into free fatty acids, which are potent acne stimuli. These free fatty acids stimulate the hair follicle, and form a comedo which is the first step of forming an acne lesion. Comedo refers to a sebum sac formed by outlet obstruction of the sebaceous glands. These bacteria also secrete leukocyte chemotatic factors, thereby infiltrating leukocytes into the hair follicle. These leukocytes stimulate and destroy the hair follicle wall. Therefore, P. acnes is considered to play an important role in acne development by secreting inflammation-inducing factors. As therapeutic agents for acne, antibiotics are usually employed to inhibit inflammation or kill the bacteria. For example, triclosan, benzyl peroxide, azelaic acid, retinoid, tetracycline, erythromycin, macrolide and clindamycin are among these antibiotics. However, these antibiotics have been known to induce side effects. Benzyl peroxide and retinoid bring about xerosis cutis and skin irritation if they are used excessively as treatments, and several reports also suggest that in the case of tetracycline, erythromycin, macrolide and clindamycin, there are several side effects such as appearance of resistant bacteria, organ damage, and immunohypersensitivity if they have been taken for a long time. In addition, triclosan is converted into an environmental hormone when exposed to light, inducing severe environmental pollution. Therefore, there is a need for substances which have no side effects and exhibit a strong antibacterial activity.
Meanwhile, Aceriphyllum rossii is a perennial herb with a height of 10-30 cm, which belongs to the family Saxifragaceae of the order Rosales of the class Dicotyledoneae, and also called Mukdenia or Saxifraga. The leaves of Aceriphyllum rossii resemble maple leaves, and it can be grown in a rock garden, and thus is also called a rock maple. The flower and palm-like leaves of Aceriphyllum rossii have 5-7 deeply divided, serrated lobes, and their surfaces are glossy. Young leaves, in particular, are used for food. Since Aceriphyllum rossii has cardiotonic and diuretic effects, 10-15 g of Aceriphyllum rossii may be extracted with boiling water, and taken to treat palpitation and urinary disorder. As a home remedy, the roots may serve as a substitute for Acorns gramineus. Aceriphyllum rossii includes the active ingredients of triterpenes and flavonoids. It has been reported that triterpenes have cytotoxicity against cancer cells (K562, HL-60) and ACAT inhibitory activity, and flavonoids show antioxidant activity (Han et al., Arch Pharm Res 27:390-395, 2004).
As described above, various pharmacological activities of Aceriphyllum rossii have been reported, but there has been no report on the antibacterial activity of Aceriphyllum rossii. 